1. Field of the Invention
The invention relates to a method of making magnetic head sliders to be used in magnetomotive storage apparatus, based on a flat workpiece out of which several magnetic head sliders equipped with rails and magnetic heads are manufactured simultaneously.
2. Description of the Prior Art
The magnetic head consists of an electromagnetic or magnetic arrangement for writing, reading or erasing data on a magnetizable storage medium movable relative thereto which in the described embodiment however consists of a magnetic disk. All known kinds of magnetic head arrangement can be used, as ring electromagnets with air gap, Hall effect components, magneto-resistive components, etc., although the embodiment described refers to an inductive electromagnetic arrangement exclusively.
A magnetic head slider of that kind as it forms the basis of the invention, is known from U.S. Pat. No. 3,855,625 which describes the essential features. The description given there depicts not only where the magnetic heads are attached to the magnetic head slider, but also that the latter can have a great variety of shapes at its trailing edge, if the magnetic head-equipped surface is considered to be the leading edge. The embodiment described there specifies in particular that apart from the longitudinal rails an additional cross rail is provided. The respective rail design is directed to aerodynamic characteristics, and can therefore be disregarded in connection with the present invention, as the method as disclosed by the invention can be considered to be substantially independent thereof. Concerning the embodiment described therefore a magnetic head slider with merely two longitudinal rails is referred to for better understanding.
Typical dimensions for such magnetic head sliders are: 4.times.3 mm with a rail width of 0.5 mm and a rail depth between 5 and 20 .mu.m. The magnetic head slider consists of ceramic and is shaped out of a square workpiece of corresponding dimensions by means of grinding, chemical etching, cathode sputter etching, or ion beam etching; i.e. between the surface regions provided for the rails the material of the magnetic head slider is etched off down to the depth corresponding to the necessary rail height. The rail surfaces are lapped, so that the peak-to-valley height is made to reach a value of less than 25 nm. For manufacture, the workpiece can be such that several magnetic head sliders can be made simultaneously. Following the final process step, the workpiece merely has to be divided into the individual magnetic head sliders.
Owing to the fact that the workpiece consists of ceramic material, process problems arise which are even intensified and increased by the use of the necessary mask process steps.